Add threads using Rayon

5 files changed, 38 insertions, 21 deletions

diff --git a/src/hittable.rs b/src/hittable.rs
index 1c61872..dcc5006 100644
--- a/src/hittable.rs
+++ b/src/hittable.rs
@@ -7,11 +7,12 @@ pub struct Hit<'a> {
     pub p: Vector3<f64>,
     pub normal: Vector3<f64>,
     pub front_face: bool,
-    pub material: &'a (dyn Material)
+    pub material: &'a (dyn Material + std::marker::Sync)
 }
 
 impl<'a> Hit<'a> {
-    pub fn new(ray: &Ray, t: f64, out_normal: Vector3<f64>, material: &'a(dyn Material)) -> Hit<'a> {
+    pub fn new(ray: &Ray, t: f64, out_normal: Vector3<f64>, material: &'a(dyn Material + std::marker::Sync))
+               -> Hit<'a> {
         let front_face = dot(ray.dir, out_normal) < 0.0;
         let normal = if front_face { out_normal } else { -out_normal };
         let p = ray.at(t);
diff --git a/src/main.rs b/src/main.rs
index 1a0b001..f1a627f 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -59,9 +59,10 @@ pub fn random_scene(rng: &mut ThreadRng) -> scene::Scene {
 }
 
 fn main() {
-    let image_width = 1200;
-    let image_height = 800;
-    let samples = 100;
+    let image_width = 400;
+    let image_height = 200;
+    let samples = 50;
+    let threads = 1;
     let max_depth = 50;
     let aspect_ratio = image_width as f64 / image_height as f64;
 
@@ -78,7 +79,7 @@ fn main() {
     let camera = camera::Camera::new(&lookfrom, &lookat, &vup,
                                      20.0 * PI / 180.0, aspect_ratio, aperture, dist_to_focus);
 
-    render::render(&scene, camera, image_height, image_width, samples, max_depth, &mut rng);
+    render::render(&scene, &camera, image_height, image_width, samples, max_depth, threads);
 
     eprintln!("\nDone")
 }
diff --git a/src/render.rs b/src/render.rs
index 740c3eb..47c6698 100644
--- a/src/render.rs
+++ b/src/render.rs
@@ -1,6 +1,7 @@
 use cgmath::prelude::*;
 use cgmath::{Vector3, vec3};
 use rand::prelude::*;
+use rayon::prelude::*;
 use std::f64::INFINITY;
 use crate::camera::Camera;
 use crate::scene::Scene;
@@ -23,20 +24,34 @@ fn ray_colour(rng: &mut ThreadRng, ray: &Ray, scene: &Scene, depth: i32) -> Vect
     }
 }
 
-pub fn render(world: &Scene, camera: Camera, image_height: i32, image_width: i32,
-          samples: i32, max_depth: i32, rng: &mut ThreadRng) {
+pub fn thread_render(world: &Scene, camera: &Camera, rng: &mut ThreadRng, image_height: i32,
+                     image_width: i32, samples: i32, max_depth: i32, i: i32, j: i32) -> Vector3<f64> {
+    let mut colour = vec3(0.0, 0.0, 0.0);
+    for _ in 0 .. samples {
+        let ru: f64 = rng.gen();
+        let rv: f64 = rng.gen();
+        let u = (i as f64 + ru) / image_width as f64;
+        let v = ((image_height - 1 - j) as f64 + rv) / image_height as f64;
+        let ray = camera.get_ray(rng, u, v);
+        colour += ray_colour(rng, &ray, &world, max_depth);
+    }
+    colour
+}
+
+pub fn render(world: &Scene, camera: &Camera, image_height: i32, image_width: i32,
+              samples: i32, max_depth: i32, threads: i32) {
     for j in 0 .. image_height {
         eprint!("\rScanlines: {:3} / {:3}", j+1, image_height);
         for i in 0 .. image_width  {
-            let mut colour = vec3(0.0, 0.0, 0.0);
-            for _ in 0 .. samples {
-                let ru: f64 = rng.gen();
-                let rv: f64 = rng.gen();
-                let u = (i as f64 + ru) / image_width as f64;
-                let v = ((image_height - 1 - j) as f64 + rv) / image_height as f64;
-                let ray = camera.get_ray(rng, u, v);
-                colour += ray_colour(rng, &ray, &world, max_depth);
-            }
+            let colours = (0 .. threads)
+                .into_par_iter()
+                .map(|_| {
+                     let mut trng = thread_rng();
+                     thread_render(
+                         world, camera, &mut trng, image_height, image_width,
+                         samples / threads, max_depth, i, j)
+                });
+            let colour = colours.sum::<Vector3<f64>>();
             print_colour(&colour, samples);
         }
     }
diff --git a/src/scene.rs b/src/scene.rs
index 368c784..0aa775c 100644
--- a/src/scene.rs
+++ b/src/scene.rs
@@ -2,7 +2,7 @@ use crate::hittable::{Hittable, Hit};
 use crate::ray::Ray;
 
 pub struct Scene {
-    objects: Vec<Box<dyn Hittable>>
+    objects: Vec<Box<dyn Hittable + std::marker::Sync>>
 }
 
 impl Scene {
@@ -10,7 +10,7 @@ impl Scene {
         Scene { objects: Vec::new() }
     }
 
-    pub fn add(&mut self, obj: Box<dyn Hittable>) {
+    pub fn add(&mut self, obj: Box<dyn Hittable + std::marker::Sync>) {
         self.objects.push(obj)
     }
 
diff --git a/src/sphere.rs b/src/sphere.rs
index 9ea9081..f1c88b6 100644
--- a/src/sphere.rs
+++ b/src/sphere.rs
@@ -8,11 +8,11 @@ use crate::ray::Ray;
 pub struct Sphere {
     center: Vector3<f64>,
     radius: f64,
-    material: Box<dyn Material>
+    material: Box<dyn Material + std::marker::Sync>
 }
 
 impl Sphere {
-    pub fn new(center: Vector3<f64>, radius: f64, material: Box<dyn Material>) -> Sphere {
+    pub fn new(center: Vector3<f64>, radius: f64, material: Box<dyn Material + std::marker::Sync>) -> Sphere {
         Sphere { center, radius, material }
     }
 }